#!/bin/bash

# -------------------------------------------------------------------------- #
# Copyright 2002-2023, OpenNebula Project, OpenNebula Systems                #
#                                                                            #
# Licensed under the Apache License, Version 2.0 (the "License"); you may    #
# not use this file except in compliance with the License. You may obtain    #
# a copy of the License at                                                   #
#                                                                            #
# http://www.apache.org/licenses/LICENSE-2.0                                 #
#                                                                            #
# Unless required by applicable law or agreed to in writing, software        #
# distributed under the License is distributed on an "AS IS" BASIS,          #
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   #
# See the License for the specific language governing permissions and        #
# limitations under the License.                                             #
#--------------------------------------------------------------------------- #

###############################################################################
# This script is used to monitor the free and used space of a datastore
###############################################################################

# -------- Set up the environment to source common tools & conf ------------

if [ -z "${ONE_LOCATION}" ]; then
    LIB_LOCATION=/usr/lib/one
else
    LIB_LOCATION=$ONE_LOCATION/lib
fi

. $LIB_LOCATION/sh/scripts_common.sh

DRIVER_PATH=$(dirname $0)
source ${DRIVER_PATH}/../../datastore/libfs.sh

# -------- Get datastore arguments from OpenNebula core ------------

DRV_ACTION=`cat -`
DS_ID=$1

XPATH="${DRIVER_PATH}/../../datastore/xpath.rb -b $DRV_ACTION"

unset i XPATH_ELEMENTS

while IFS= read -r -d '' ELEMENT; do
    XPATH_ELEMENTS[i++]="$ELEMENT"
done < <($XPATH     /DS_DRIVER_ACTION_DATA/DATASTORE_LOCATION \
                    /DS_DRIVER_ACTION_DATA/DATASTORE/TEMPLATE/BRIDGE_LIST \
                    /DS_DRIVER_ACTION_DATA/MONITOR_VM_DISKS)

unset i

BASE_PATH="${XPATH_ELEMENTS[i++]}/$DS_ID"
BRIDGE_LIST="${XPATH_ELEMENTS[i++]}"
MONITOR_VM_DISKS="${XPATH_ELEMENTS[i++]}"

# ------------ Compute datastore usage -------------

LVM_VG_PREFIX="vg-one-"

MONITOR_SCRIPT=$(cat <<EOF
if [ ! -d $BASE_PATH ]; then
    mkdir -p $BASE_PATH
fi

# If vg-one-$DS_ID exists, we assume it's an fs_lvm image datastore, therefore'
# we return the space of the lvm, no of the filesystem
if PATH=\$PATH:/sbin:/bin:/usr/sbin:/usr/bin which vgdisplay &> /dev/null; then
    LVM_SIZE=\$($SUDO $VGDISPLAY \
                    --separator : \
                    --units m \
                    -o vg_size,vg_free \
                    --nosuffix \
                    --noheadings \
                    -C \
                    ${LVM_VG_PREFIX}${DS_ID} 2>/dev/null)
fi

if [ -n "\$LVM_SIZE" ]; then
    LVM_TOTAL=\$(echo \$LVM_SIZE | cut -d: -f1 | sed 's/\..*//;s/^\s*//')
    LVM_FREE=\$(echo \$LVM_SIZE | cut -d: -f2 | sed 's/\..*//;s/^\s*//')
    LVM_USED=\$(( \$LVM_TOTAL - \$LVM_FREE ))

    TOTAL_MB=\${LVM_TOTAL:-"0"}
    FREE_MB=\${LVM_FREE:-"0"}
    USED_MB=\${LVM_USED:-"0"}
else
    USED_MB=\$(df -B1M -P $BASE_PATH 2>/dev/null | tail -n 1 | awk '{print \$3}')
    TOTAL_MB=\$(df -B1M -P $BASE_PATH 2>/dev/null | tail -n 1 | awk '{print \$2}')
    FREE_MB=\$(df -B1M -P $BASE_PATH 2>/dev/null | tail -n 1 | awk '{print \$4}')
fi

if [ -z "\$USED_MB" -o -z "\$TOTAL_MB" -o -z "\$FREE_MB" ]; then
    MSG="Empty value found"
    echo "\$MSG: USED_MB=\$USED_MB, TOTAL_MB=\$TOTAL_MB, FREE_MB=\$FREE_MB"
    exit 1
fi

echo "USED_MB=\$USED_MB"
echo "FREE_MB=\$FREE_MB"
echo "TOTAL_MB=\$TOTAL_MB"

EOF
)

MONITOR_VM_SCRIPT=$(cat <<EOF
LVDATA=\$($SUDO $LVS --noheadings --nosuffix --units m -o lv_name,lv_size --separator : "${LVM_VG_PREFIX}${DS_ID}" | sed -e 's/^[[:space:]]*//' | grep '^lv-one-' | sed 's/^lv-one-//' | tr '-' ':' | sort -n)
[ -z "\$LVDATA" ] && exit 0

VM_PREVIOUS='n'

while IFS="\n" read -r LINE; do
    VM=\$(echo "\$LINE" | cut -d':' -f1)
    [ -n "\$VM" ] || continue

    DISK=\$(echo "\$LINE" | cut -d':' -f2)
    SIZE=\$(echo "\$LINE" | cut -d':' -f3 | cut -d'.' -f1)

    if [ "\$VM" != "\$VM_PREVIOUS" ]; then
        [ "\$VM_PREVIOUS" != "n" ] && echo "\"]"

        VM_PREVIOUS="\$VM"
        echo -n "VM=[ID=\$VM,MONITOR=\""
    else
        echo -n " "
    fi

    MONITOR_B64="\$(echo -n "DISK_SIZE=[ID=\$DISK,SIZE=\$SIZE]" | base64 -w 0)"
    echo -n "\$MONITOR_B64"

done <<< "\$( echo "\$LVDATA" )"

[ "\$VM_PREVIOUS" != "n" ] && echo "\"]"

EOF
)

if [ -n "$BRIDGE_LIST" ]; then
    HOST=`get_destination_host`
    MONITOR_DATA=$(ssh_monitor_and_log "$HOST" "$MONITOR_SCRIPT" "Remote monitor script" 2>&1)
    MONITOR_STATUS=$?

    if [ $MONITOR_VM_DISKS -eq 1 ]; then
        MONITOR_DATA_VMS=$(ssh_monitor_and_log "$HOST" "$MONITOR_VM_SCRIPT" "Remote VM disks monitor script" 2>&1)
        MONITOR_VMS_STATUS=$?
    fi
else
    MONITOR_DATA=$(monitor_and_log "$MONITOR_SCRIPT" "Monitor script" 2>&1)
    MONITOR_STATUS=$?

    if [ $MONITOR_VM_DISKS -eq 1 ]; then
        MONITOR_DATA_VMS=$(monitor_and_log "$MONITOR_VM_SCRIPT" "VM disks monitor script" 2>&1)
        MONITOR_VMS_STATUS=$?
    fi
fi

echo $MONITOR_DATA

if [ $MONITOR_VM_DISKS -eq 1 ]; then
    send_to_monitor MONITOR_VM $MONITOR_VMS_STATUS -1 "$MONITOR_DATA_VMS"
fi

exit $MONITOR_STATUS
